Identification of Peripheral Fatigue through Exercise-Induced Changes in Muscle Contractility

Area of Science:

• Sports Science
• Exercise Physiology
• Biomedical Engineering

Background:

• Peripheral fatigue is a crucial factor influencing athletic performance and training.
• Accurate and sensitive methods are needed to quantify muscle fatigue during and after exercise.
• Tensiomyography (TMG) is a non-invasive technique measuring muscle mechanical properties.

Purpose of the Study:

• To evaluate the sensitivity of tensiomyography (TMG) in detecting peripheral muscle fatigue.
• To compare TMG parameters with traditional fatigue measures like countermovement jump (CMJ) and maximal isometric force (MIF).
• To identify specific TMG variables predictive of fatigue in resistance-trained individuals.

Main Methods:

• Twenty-six strength-trained men were divided into a fatigued group (performing squats) and a non-fatigued control group.
• Measurements included countermovement jump (CMJ), maximal isometric force (MIF), and TMG of vastus medialis (VM) and vastus lateralis (VL) muscles.
• Statistical analyses included mixed ANOVA, logistic regression, and receiver-operating characteristic (ROC) curve analysis.

Main Results:

• Significant group-by-time interactions were observed for CMJ, MIF, TMG's maximal radial displacement (Dm), and radial displacement velocity (Vrd90), indicating fatigue in the experimental group.
• Logistic regression identified the relative change in VL-Vrd90 as a significant predictor of fatigue.
• ROC analysis demonstrated good to excellent discriminative ability for Dm and Vrd90 in detecting muscle fatigue.

Conclusions:

• Tensiomyography (TMG) demonstrates high sensitivity in detecting peripheral muscle fatigue induced by resistance exercise.
• Specific TMG parameters, particularly Dm and Vrd90 in the vastus lateralis and medialis muscles, are effective indicators of fatigue.
• TMG serves as a valuable tool for assessing muscle fatigue in resistance training contexts.